Stone Disease of the Gastrointestinal tract affects over 16 million people in the U.S. Approximately 1 million new cases of cholelethiasis develop each year and surgical intervention was required in 554,000 procedures in 1984. The average length of hospitalization for these patients is between 9 and 16 days. Candela has performed in-vitro and animal studies under the confines of the Phase I Grant to establish optimum laser parameters for safe and effective fragmentation of biliary stones. In Phase II, we propose to develop more effective delivery systems including: 1) refinement of a laser basket and a laser balloon with a channel to accept the Candela laser fiber, 2) development of a duodenoscope that accepts the Candela fiber and a guidewire and, 3) a radio opaque fiber that can be used for fluoroscopic lithotripsy. We will also perform a three site multi-center trial. If successful, this research will lead to commercialization of a clinical system.